1. **State the problem:**
We have two parabolas given by the equations:
$$y = x^2 - c^2$$
and
$$y = c^2 - x^2$$
These parabolas bound a region whose area is 1944. We need to find the value of $c$.
2. **Understand the region bounded:**
The region bounded by these curves is where the two parabolas intersect. Since one is $y = x^2 - c^2$ (opening upwards shifted down by $c^2$) and the other is $y = c^2 - x^2$ (opening downwards shifted up by $c^2$), the region is symmetric about the y-axis.
3. **Find the points of intersection:**
Set the two equations equal:
$$x^2 - c^2 = c^2 - x^2$$
Simplify:
$$x^2 - c^2 = c^2 - x^2$$
$$x^2 + x^2 = c^2 + c^2$$
$$2x^2 = 2c^2$$
$$\cancel{2}x^2 = \cancel{2}c^2$$
$$x^2 = c^2$$
So,
$$x = \pm c$$
4. **Set up the integral for the area:**
The area between the curves from $x = -c$ to $x = c$ is:
$$A = \int_{-c}^c \big[(c^2 - x^2) - (x^2 - c^2)\big] \, dx$$
Simplify the integrand:
$$(c^2 - x^2) - (x^2 - c^2) = c^2 - x^2 - x^2 + c^2 = 2c^2 - 2x^2$$
5. **Calculate the integral:**
$$A = \int_{-c}^c (2c^2 - 2x^2) \, dx = 2 \int_{-c}^c (c^2 - x^2) \, dx$$
Because the function is even, we can write:
$$A = 2 \times 2 \int_0^c (c^2 - x^2) \, dx = 4 \int_0^c (c^2 - x^2) \, dx$$
6. **Evaluate the integral:**
$$\int_0^c (c^2 - x^2) \, dx = \left[c^2 x - \frac{x^3}{3}\right]_0^c = c^3 - \frac{c^3}{3} = \frac{2c^3}{3}$$
7. **Calculate total area:**
$$A = 4 \times \frac{2c^3}{3} = \frac{8c^3}{3}$$
8. **Use the given area to solve for $c$:**
$$\frac{8c^3}{3} = 1944$$
Multiply both sides by 3:
$$8c^3 = 1944 \times 3 = 5832$$
Divide both sides by 8:
$$c^3 = \frac{5832}{8} = 729$$
9. **Find $c$:**
$$c = \sqrt[3]{729} = 9$$
**Final answer:**
$$\boxed{9}$$
Parabola Area 1A4A71
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